V4L/DVB (12275): Add two new ioctls: DMX_ADD_PID and DMX_REMOVE_PID

DMX_ADD_PID allows to add multiple PIDs to a transport stream filter
previously set up with DMX_SET_PES_FILTER and output=DMX_OUT_TSDEMUX_TAP.

DMX_REMOVE_PID is used to drop a PID from a filter.

These ioctls are to be used by readers of /dev/dvb/adapterX/demuxY. They
may be called at any time, i.e. before or after the first filter on the
shared file descriptor was started.

They make it possible to record multiple services without the need to de-
or re-multiplex TS packets.

To accomplish this, dmxdev_filter->feed.ts has been converted to a list
of struct dmxdev_feeds, each containing a PID value and a pointer to a
struct dmx_ts_feed.
Signed-off-by: Andreas Oberritter <obi@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/dvb-core/dmxdev.c

@@ -430,6 +430,8 @@ static int dvb_dmxdev_ts_callback(const u8 *buffer1, size_t buffer1_len,
 /* stop feed but only mark the specified filter as stopped (state set) */
 static int dvb_dmxdev_feed_stop(struct dmxdev_filter *dmxdevfilter)
 {
+	struct dmxdev_feed *feed;
+
 	dvb_dmxdev_filter_state_set(dmxdevfilter, DMXDEV_STATE_SET);
 
 	switch (dmxdevfilter->type) {
@@ -438,7 +440,8 @@ static int dvb_dmxdev_feed_stop(struct dmxdev_filter *dmxdevfilter)
 		dmxdevfilter->feed.sec->stop_filtering(dmxdevfilter->feed.sec);
 		break;
 	case DMXDEV_TYPE_PES:
-		dmxdevfilter->feed.ts->stop_filtering(dmxdevfilter->feed.ts);
+		list_for_each_entry(feed, &dmxdevfilter->feed.ts, next)
+			feed->ts->stop_filtering(feed->ts);
 		break;
 	default:
 		return -EINVAL;
@@ -449,13 +452,23 @@ static int dvb_dmxdev_feed_stop(struct dmxdev_filter *dmxdevfilter)
 /* start feed associated with the specified filter */
 static int dvb_dmxdev_feed_start(struct dmxdev_filter *filter)
 {
+	struct dmxdev_feed *feed;
+	int ret;
+
 	dvb_dmxdev_filter_state_set(filter, DMXDEV_STATE_GO);
 
 	switch (filter->type) {
 	case DMXDEV_TYPE_SEC:
 		return filter->feed.sec->start_filtering(filter->feed.sec);
 	case DMXDEV_TYPE_PES:
-		return filter->feed.ts->start_filtering(filter->feed.ts);
+		list_for_each_entry(feed, &filter->feed.ts, next) {
+			ret = feed->ts->start_filtering(feed->ts);
+			if (ret < 0) {
+				dvb_dmxdev_feed_stop(filter);
+				return ret;
+			}
+		}
+		break;
 	default:
 		return -EINVAL;
 	}
@@ -487,6 +500,9 @@ static int dvb_dmxdev_feed_restart(struct dmxdev_filter *filter)
 
 static int dvb_dmxdev_filter_stop(struct dmxdev_filter *dmxdevfilter)
 {
+	struct dmxdev_feed *feed;
+	struct dmx_demux *demux;
+
 	if (dmxdevfilter->state < DMXDEV_STATE_GO)
 		return 0;
 
@@ -503,13 +519,12 @@ static int dvb_dmxdev_filter_stop(struct dmxdev_filter *dmxdevfilter)
 		dmxdevfilter->feed.sec = NULL;
 		break;
 	case DMXDEV_TYPE_PES:
-		if (!dmxdevfilter->feed.ts)
-			break;
 		dvb_dmxdev_feed_stop(dmxdevfilter);
-		dmxdevfilter->dev->demux->
-		    release_ts_feed(dmxdevfilter->dev->demux,
-				    dmxdevfilter->feed.ts);
-		dmxdevfilter->feed.ts = NULL;
+		demux = dmxdevfilter->dev->demux;
+		list_for_each_entry(feed, &dmxdevfilter->feed.ts, next) {
+			demux->release_ts_feed(demux, feed->ts);
+			feed->ts = NULL;
+		}
 		break;
 	default:
 		if (dmxdevfilter->state == DMXDEV_STATE_ALLOCATED)
@@ -521,19 +536,88 @@ static int dvb_dmxdev_filter_stop(struct dmxdev_filter *dmxdevfilter)
 	return 0;
 }
 
+static void dvb_dmxdev_delete_pids(struct dmxdev_filter *dmxdevfilter)
+{
+	struct dmxdev_feed *feed, *tmp;
+
+	/* delete all PIDs */
+	list_for_each_entry_safe(feed, tmp, &dmxdevfilter->feed.ts, next) {
+		list_del(&feed->next);
+		kfree(feed);
+	}
+
+	BUG_ON(!list_empty(&dmxdevfilter->feed.ts));
+}
+
 static inline int dvb_dmxdev_filter_reset(struct dmxdev_filter *dmxdevfilter)
 {
 	if (dmxdevfilter->state < DMXDEV_STATE_SET)
 		return 0;
 
+	if (dmxdevfilter->type == DMXDEV_TYPE_PES)
+		dvb_dmxdev_delete_pids(dmxdevfilter);
+
 	dmxdevfilter->type = DMXDEV_TYPE_NONE;
 	dvb_dmxdev_filter_state_set(dmxdevfilter, DMXDEV_STATE_ALLOCATED);
 	return 0;
 }
 
+static int dvb_dmxdev_start_feed(struct dmxdev *dmxdev,
+				 struct dmxdev_filter *filter,
+				 struct dmxdev_feed *feed)
+{
+	struct timespec timeout = { 0 };
+	struct dmx_pes_filter_params *para = &filter->params.pes;
+	dmx_output_t otype;
+	int ret;
+	int ts_type;
+	enum dmx_ts_pes ts_pes;
+	struct dmx_ts_feed *tsfeed;
+
+	feed->ts = NULL;
+	otype = para->output;
+
+	ts_pes = (enum dmx_ts_pes)para->pes_type;
+
+	if (ts_pes < DMX_PES_OTHER)
+		ts_type = TS_DECODER;
+	else
+		ts_type = 0;
+
+	if (otype == DMX_OUT_TS_TAP)
+		ts_type |= TS_PACKET;
+	else if (otype == DMX_OUT_TSDEMUX_TAP)
+		ts_type |= TS_PACKET | TS_DEMUX;
+	else if (otype == DMX_OUT_TAP)
+		ts_type |= TS_PACKET | TS_DEMUX | TS_PAYLOAD_ONLY;
+
+	ret = dmxdev->demux->allocate_ts_feed(dmxdev->demux, &feed->ts,
+					      dvb_dmxdev_ts_callback);
+	if (ret < 0)
+		return ret;
+
+	tsfeed = feed->ts;
+	tsfeed->priv = filter;
+
+	ret = tsfeed->set(tsfeed, feed->pid, ts_type, ts_pes, 32768, timeout);
+	if (ret < 0) {
+		dmxdev->demux->release_ts_feed(dmxdev->demux, tsfeed);
+		return ret;
+	}
+
+	ret = tsfeed->start_filtering(tsfeed);
+	if (ret < 0) {
+		dmxdev->demux->release_ts_feed(dmxdev->demux, tsfeed);
+		return ret;
+	}
+
+	return 0;
+}
+
 static int dvb_dmxdev_filter_start(struct dmxdev_filter *filter)
 {
 	struct dmxdev *dmxdev = filter->dev;
+	struct dmxdev_feed *feed;
 	void *mem;
 	int ret, i;
 
@@ -631,56 +715,14 @@ static int dvb_dmxdev_filter_start(struct dmxdev_filter *filter)
 		break;
 	}
 	case DMXDEV_TYPE_PES:
-	{
-		struct timespec timeout = { 0 };
-		struct dmx_pes_filter_params *para = &filter->params.pes;
-		dmx_output_t otype;
-		int ts_type;
-		enum dmx_ts_pes ts_pes;
-		struct dmx_ts_feed **tsfeed = &filter->feed.ts;
-
-		filter->feed.ts = NULL;
-		otype = para->output;
-
-		ts_pes = (enum dmx_ts_pes)para->pes_type;
-
-		if (ts_pes < DMX_PES_OTHER)
-			ts_type = TS_DECODER;
-		else
-			ts_type = 0;
-
-		if (otype == DMX_OUT_TS_TAP)
-			ts_type |= TS_PACKET;
-		else if (otype == DMX_OUT_TSDEMUX_TAP)
-			ts_type |= TS_PACKET | TS_DEMUX;
-		else if (otype == DMX_OUT_TAP)
-			ts_type |= TS_PACKET | TS_DEMUX | TS_PAYLOAD_ONLY;
-
-		ret = dmxdev->demux->allocate_ts_feed(dmxdev->demux,
-						      tsfeed,
-						      dvb_dmxdev_ts_callback);
-		if (ret < 0)
-			return ret;
-
-		(*tsfeed)->priv = filter;
-
-		ret = (*tsfeed)->set(*tsfeed, para->pid, ts_type, ts_pes,
-				     32768, timeout);
-		if (ret < 0) {
-			dmxdev->demux->release_ts_feed(dmxdev->demux,
-						       *tsfeed);
-			return ret;
-		}
-
-		ret = filter->feed.ts->start_filtering(filter->feed.ts);
-		if (ret < 0) {
-			dmxdev->demux->release_ts_feed(dmxdev->demux,
-						       *tsfeed);
-			return ret;
+		list_for_each_entry(feed, &filter->feed.ts, next) {
+			ret = dvb_dmxdev_start_feed(dmxdev, filter, feed);
+			if (ret < 0) {
+				dvb_dmxdev_filter_stop(filter);
+				return ret;
+			}
 		}
-
 		break;
-	}
 	default:
 		return -EINVAL;
 	}
@@ -718,7 +760,7 @@ static int dvb_demux_open(struct inode *inode, struct file *file)
 	dvb_ringbuffer_init(&dmxdevfilter->buffer, NULL, 8192);
 	dmxdevfilter->type = DMXDEV_TYPE_NONE;
 	dvb_dmxdev_filter_state_set(dmxdevfilter, DMXDEV_STATE_ALLOCATED);
-	dmxdevfilter->feed.ts = NULL;
+	INIT_LIST_HEAD(&dmxdevfilter->feed.ts);
 	init_timer(&dmxdevfilter->timer);
 
 	dvbdev->users++;
@@ -760,6 +802,55 @@ static inline void invert_mode(dmx_filter_t *filter)
 		filter->mode[i] ^= 0xff;
 }
 
+static int dvb_dmxdev_add_pid(struct dmxdev *dmxdev,
+			      struct dmxdev_filter *filter, u16 pid)
+{
+	struct dmxdev_feed *feed;
+
+	if ((filter->type != DMXDEV_TYPE_PES) ||
+	    (filter->state < DMXDEV_STATE_SET))
+		return -EINVAL;
+
+	/* only TS packet filters may have multiple PIDs */
+	if ((filter->params.pes.output != DMX_OUT_TSDEMUX_TAP) &&
+	    (!list_empty(&filter->feed.ts)))
+		return -EINVAL;
+
+	feed = kzalloc(sizeof(struct dmxdev_feed), GFP_KERNEL);
+	if (feed == NULL)
+		return -ENOMEM;
+
+	feed->pid = pid;
+	list_add(&feed->next, &filter->feed.ts);
+
+	if (filter->state >= DMXDEV_STATE_GO)
+		return dvb_dmxdev_start_feed(dmxdev, filter, feed);
+
+	return 0;
+}
+
+static int dvb_dmxdev_remove_pid(struct dmxdev *dmxdev,
+				  struct dmxdev_filter *filter, u16 pid)
+{
+	struct dmxdev_feed *feed, *tmp;
+
+	if ((filter->type != DMXDEV_TYPE_PES) ||
+	    (filter->state < DMXDEV_STATE_SET))
+		return -EINVAL;
+
+	list_for_each_entry_safe(feed, tmp, &filter->feed.ts, next) {
+		if ((feed->pid == pid) && (feed->ts != NULL)) {
+			feed->ts->stop_filtering(feed->ts);
+			filter->dev->demux->release_ts_feed(filter->dev->demux,
+							    feed->ts);
+			list_del(&feed->next);
+			kfree(feed);
+		}
+	}
+
+	return 0;
+}
+
 static int dvb_dmxdev_filter_set(struct dmxdev *dmxdev,
 				 struct dmxdev_filter *dmxdevfilter,
 				 struct dmx_sct_filter_params *params)
@@ -784,7 +875,10 @@ static int dvb_dmxdev_pes_filter_set(struct dmxdev *dmxdev,
 				     struct dmxdev_filter *dmxdevfilter,
 				     struct dmx_pes_filter_params *params)
 {
+	int ret;
+
 	dvb_dmxdev_filter_stop(dmxdevfilter);
+	dvb_dmxdev_filter_reset(dmxdevfilter);
 
 	if (params->pes_type > DMX_PES_OTHER || params->pes_type < 0)
 		return -EINVAL;
@@ -795,6 +889,11 @@ static int dvb_dmxdev_pes_filter_set(struct dmxdev *dmxdev,
 
 	dvb_dmxdev_filter_state_set(dmxdevfilter, DMXDEV_STATE_SET);
 
+	ret = dvb_dmxdev_add_pid(dmxdev, dmxdevfilter,
+				 dmxdevfilter->params.pes.pid);
+	if (ret < 0)
+		return ret;
+
 	if (params->flags & DMX_IMMEDIATE_START)
 		return dvb_dmxdev_filter_start(dmxdevfilter);
 
@@ -958,6 +1057,24 @@ static int dvb_demux_do_ioctl(struct inode *inode, struct file *file,
 					     &((struct dmx_stc *)parg)->base);
 		break;
 
+	case DMX_ADD_PID:
+		if (mutex_lock_interruptible(&dmxdevfilter->mutex)) {
+			ret = -ERESTARTSYS;
+			break;
+		}
+		ret = dvb_dmxdev_add_pid(dmxdev, dmxdevfilter, *(u16 *)parg);
+		mutex_unlock(&dmxdevfilter->mutex);
+		break;
+
+	case DMX_REMOVE_PID:
+		if (mutex_lock_interruptible(&dmxdevfilter->mutex)) {
+			ret = -ERESTARTSYS;
+			break;
+		}
+		ret = dvb_dmxdev_remove_pid(dmxdev, dmxdevfilter, *(u16 *)parg);
+		mutex_unlock(&dmxdevfilter->mutex);
+		break;
+
 	default:
 		ret = -EINVAL;
 		break;

drivers/media/dvb/dvb-core/dmxdev.h

@@ -53,13 +53,20 @@ enum dmxdev_state {
 	DMXDEV_STATE_TIMEDOUT
 };
 
+struct dmxdev_feed {
+	u16 pid;
+	struct dmx_ts_feed *ts;
+	struct list_head next;
+};
+
 struct dmxdev_filter {
 	union {
 		struct dmx_section_filter *sec;
 	} filter;
 
 	union {
-		struct dmx_ts_feed *ts;
+		/* list of TS and PES feeds (struct dmxdev_feed) */
+		struct list_head ts;
 		struct dmx_section_feed *sec;
 	} feed;
 

include/linux/dvb/dmx.h

@@ -151,5 +151,7 @@ struct dmx_stc {
 #define DMX_GET_CAPS             _IOR('o', 48, dmx_caps_t)
 #define DMX_SET_SOURCE           _IOW('o', 49, dmx_source_t)
 #define DMX_GET_STC              _IOWR('o', 50, struct dmx_stc)
+#define DMX_ADD_PID              _IOW('o', 51, __u16)
+#define DMX_REMOVE_PID           _IOW('o', 52, __u16)
 
 #endif /*_DVBDMX_H_*/